Silver packs a punch as chemotherapy drug

SILVER may have just become even more precious. The metal packs as much of a punch against cancer cells as a leading chemotherapy drug, and could reduce the negative side effects that accompany such treatment.

Cisplatin, used to treat a range of cancers, contains platinum. The drug is formed from groups of molecules attached to a platinum atom, creating a compound that reacts with DNA in cancer cells. It is the molecules surrounding the metal that determine how reactive the compound is.

Previous studies have hinted that silver compounds could also kill cancer cells. So Charlotte Willans from the University of Leeds, UK, and colleagues subjected silver to the same treatment as platinum to see if they could make an effective cancer drug.

The team attached different types of carbene ligands to the silver atoms before incubating varying concentrations of the compound with breast and colon cancer cells for six days.

The silver complexes proved to be as effective as cisplatin in attacking both types of cancer cells. Complexes containing a ligand which had two bonds were more effective than those with a single bond, probably because they are more stable - meaning the compound breaks down more slowly and is active for longer (Dalton Transactions, DOI: 10.1039/C2DT12399A).

Crucially, silver is less toxic to normal cells than platinum. Willans says it is an important step in the quest for effective, non-toxic cancer treatments.

When this article was first posted, it incorrectly implied that Diana Monteiro was the lead researcher in this work.

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